1. Field of the Invention
The present invention relates to a magnetic storage device that can store information therein by using a magnetoresistive effect.
2. Description of the Related Art
Conventionally, a magnetic storage device called as a magnetic random access memory (MRAM) that can store information therein by using a magnetoresistive effect is widely known as a nonvolatile memory device that can operate at high speeds.
The magnetic storage device is required to efficiently perform writing to a magnetoresistive element in order to achieve improvement of an operation speed, reduction of writing current, and the like. For example, a magnetic storage device is proposed that includes an approximately annular magnetic yoke for concentrating a magnetic flux generated around a wiring on a magnetoresistive element (see Japanese Patent Laid-Open Publications Nos. 2000-90658 and 2004-128430, for example).
The intensity of a magnetic field generated from the magnetic yoke is determined by its material, shape, and the like. However, there was conventionally almost no specific proposal regarding the shape of the magnetic yoke and a relationship between the intensity of the magnetic field generated from the magnetic yoke and the shape of the magnetic yoke was not made apparent.